With the fast development of mobile communication technology and rapid increase of mobile communication business, problems of strong signal interference within communication zone, insufficient spectrum capacity and signal cover are faced. Multi-wave beam antennas may simultaneously generate directional pattern performances of multi wave beams and may increase network capacity. In addition, the multi-wave beam antennas are useful to obtain narrow wave beam and high gain and may decrease signal interference and increase covering distance. Therefore, the multi-wave beam antennas have broad application prospects and great value.
Butler matrix is an important part of the multi-wave beam antennas and is a key component for generating multi-wave beam characteristic. However, the Butler in the prior art is of large size, narrow frequency band and higher loss and is to be improved.